Surface Mount Technology Overview Surface Mount Technology (SMT)

Let's talk tech, people! Today's topic is Surface Mount Technology, which is a fancy way of saying we stick tiny components (aka SMDs) onto printed circuit boards (PCBs). SMT is like the superhero of electronic assembly - without it, our devices would be a hot mess of wires and bulky parts. Basically, it's the secret sauce that makes our gadgets sleek and portable. Some folks call it "surface assembly technology" but let's be real, "SMT" is way cooler. So give it up for SMT, the unsung hero of modern tech!

Relative to THT (insertion technology), SMT brings four major advantages to electronic products:

(1) High density. As the surface mount components using no lead or short lead, I / O end of the face array layout and other packaging technology, the size of the component is greatly reduced, I / O lead end greatly increased, so that the assembly density of the PCB has been greatly improved.

(2) High performance. Surface mount components without leads or short lead characteristics, reducing the parasitic inductance and capacitance of the leads, improve the high-frequency and high-speed performance of the circuit as well as the thermal efficiency of the device.

(3) low cost. The standardization of surface mount component packages and no-hole mounting characteristics, especially suitable for automated assembly, significantly reducing manufacturing costs.

(4) high reliability. Automated production technology to ensure a reliable connection of each solder joint, thus improving the reliability of electronic products. It is these four major advantages of SMT that promote its widespread use, which in turn promotes the continuous development of SMT itself.

SMT, or "Stressful Manufacturing Task" in the eyes of some, is actually a complex system made up of process, equipment, materials, testing, and even a touch of magic. 

Some may include component packaging and PCB technology as part of SMT, but it's like adding sprinkles to a cupcake - it's already pretty sweet on its own. However, these add-ons do help to optimize the process and tackle problems systematically. 

But let's not forget, component packaging and PCB technology are like peanut butter and jelly, they go hand-in-hand with SMT. They work together to create an even more efficient system, like Batman and Robin fighting crime.

SMT technology has two pillars - equipment and process. The process determines the equipment, the process determines the efficiency, the process determines the quality. In this sense, the process is the core of SMT.The goal of SMT process work is to create qualified solder joints. Good solder joints depend on the appropriate pad design, the right amount of solder paste, the right reflow soldering temperature profile, these are process conditions. The use of the same equipment, some manufacturers welding through the rate is higher, and some lower, the difference lies in the process is different, which is reflected in the "scientific, standardized, refined". For example, in the stacked package (PoP) production process of flux dip control, most companies use hexagonal comb gauge, through the measurement of the flux film thickness of the flux dip to control the height of the flux dip on the stacked BGA solder ball. This method ignores the flux film thickness measurement operation and mounter high-speed dipping differences, static measurement results do not reflect the actual dynamic dipping height, process control, but in practice there is not much difference with no control, control effect is extremely limited. Process control, if the target is wrong, the method is wrong, there is no meaning, this is the so-called "scientific". Another example of "refinement", for the stirring operation before the addition of solder paste, if you do not give the target requirements for qualified stirring, only the number of stirring requirements, everyone's stirring effect is not the same, which is the significance of "refinement". Soldering pad design, stencil design, printing support and parameter setting, reflow soldering temperature profile setting, assembly process tooling design and equipment, etc., these process methods, technical documents, tooling design is the process, they are the result of the accumulation of long-term experience and process development, is the core asset of the enterprise.